Agriculture: Citrus Pest Management Guidelines

Petal Fall

This year-round IPM program covers major pests of citrus grown in California's Central Valley.

About Petal Fall (late April through May)

  • Special issues of concern related to environmental quality: Drift, runoff, volatile organic compounds (VOCs).

What should you be doing during this time?

Look for Asian citrus psyllids on new flush if available and by using sweep sampling. Use an Asian citrus psyllid-effective insecticide if spraying for citrus thrips. Otherwise, manage according to the Pest Management Guidelines

Monitor fruit for immature citrus thrips (late April through June, or through October on lemon).

Manage if needed according to the Pest Management Guidelines.

Monitor trees for forktailed bush katydid (March through June). Use a time search or net shake to search for nymphs. Manage if needed according to the Pest Management Guidelines.

Monitor California red scale males using pheromone-baited sticky traps (March through October), plus additional methods (e.g. calculate degree days, monitor crawler tapes, and examine harvested fruit).

Look for spider mites and other mites.

Manage if needed according to the Pest Management Guidelines.

Monitor cottony cushion scale (May) to see if the vedalia beetle is providing biological control; it is too late to relocate beetles. If the threshold is exceeded, manage later according to the Pest Management Guidelines.

Examine twigs for citricola scale females to alert you whether management later may be needed. Be sure to distinguish citricola scale from brown soft scale.

Look for other pests and their damage to fruit or damage to leaves and twigs, especially:

  • European earwig (March through June) in mature trees or infesting wraps of young trees

Manage if needed according to the Pest Management Guidelines.

Look for brown garden snail.

  • Heading into warm weather, relocation of decollates is not advised.

Manage if needed according to the Pest Management Guidelines.

Use pesticides according to their labels to avoid killing honey bees.

Look for diseases that cause symptoms on fruit, leaves and twigs, and on limbs, trunks, and roots, especially:

Record the date and location of problem trees or sites. Manage if needed according to the Pest Management Guidelines.

Survey weeds. Manage vegetation if needed according to the Pest Management Guidelines.

Look for vertebrates, especially ground squirrels, pocket gophers, rabbits, and roof rats. Manage if needed according to the Pest Management Guidelines.

Provide proper cultural care and good growing conditions to improve tree health and fruit yield, including:

  • Fertilize if needed.
  • Irrigate and adjust scheduling to meet trees' varying water needs.
  • Prune if needed, such as removing dead twigs and branches to reduce bacterial blast (citrus blast) inoculum.

Determine whether application of plant growth regulator is warranted. Consider

Harvest mature fruit in coordination with other management activities to ensure good postharvest fruit quality and food safety.

  • Educate and supervise workers regarding fruit-handling Best Management Practices (BMP).
  • Inspect fruit quality before bins are moved from the picking site to identify grove areas where management practices need improvement.
Text Updated: 01/19